Nasopharyngeal carcinoma (NPC) is a tumor arising from the epithelial cells of the nasopharynx, which is located behind the nose and above the back of the throat. NPC differs significantly from other cancers of the head and neck, based on its causes, occurrence, clinical behavior, and treatment options. It is uncommon in the United States, but occurs much more frequently in other parts of the world, especially in Southeast Asia, including the Guangdong province of southern China, and Taiwan.
NPC's difficult-to-observe location behind the nose, where the nasal passages and auditory tubes join the remainder of the upper respiratory tract, creates two major hurdles for effective therapy. First, due to its hidden location, NPC is usually diagnosed quite late during its development and in fact, the diagnosis is often made by lymph node biopsy, when the primary cancer already has begun to spread to other parts of the body. Second, the anatomical position of the primary tumor is not easily amenable for surgery and local control, which is why biopsies are performed on cervical lymph node metastases, rarely on the primary tumor.
Treatment of NPC usually involves radiation therapy, chemotherapy, or a combination of the two. Surgery, which is rarely used, may be applied to remove cancerous lymph nodes in the neck area. The exact treatment plan is devised based on several factors, including stage of the cancer, overall health of the patient, and the extent of side effects the patient is willing tolerate. However, despite initially successful treatment, many patients will relapse after treatment, and management of NPC remains one of the biggest clinical challenges. Overall survival after recurrence is quite poor with median survival ranging from 7 to 22 months. B. Brennan, Nasopharyngeal carcinoma, Orphanet J Rare Dis 1 (2006) 23; S. M. Cao, et al., The prevalence and prevention of nasopharyngeal carcinoma in China, Chin J Cancer 30 (2011) 114-119; W. I. Wei, et al. Nasopharyngeal carcinoma. Lancet 365 (2005) 2041-2054; J. Tsang et al., Novel therapy for nasopharyngeal carcinoma—where are we. Oral Oncol 50 (2014) 798-801; L. Jang-Chun et al., Comparisons of quality of life for patients with nasopharyngeal carcinoma after treatment with different RT technologies, Acta Otorhinolaiyngol Ital 34 (2014) 241-246. Therefore, more effective and better-tolerated treatment options for NPC are needed.